Under VAT, the ordinary tax-payer (commercial enterprises) usually takes trade-off sale of goods. Whether the sale of goods is based on the difference invoiced? Or invoiced at the full amount of the goods? Flea charged VAT invoices if achieved, could it be deducted from input VAT?
According to "State Administration of Taxation on the issuance", a number of specific issues under VAT "notice" (Guo Shui Fa  No. 154) Article 3, it provides that tax-payers which take trade-off sale of goods, the goods shall be in the new year, the selling price of the sales. So, if it takes trade-off sale of goods, the sales prices over the same period and the goods shall be invoiced and tax. Collecting the old goods will obtain VAT invoices indicated the VAT that can be deducted.